Selective anticancer activity of pure licamichauxiioic-B acid in cultured cell lines

The cytotoxic activities of crude extract and pure licamichauxiioic-B compound from stem and root parts of Licania michauxii Prance (LMP) plant were evaluated against brine shrimp larvae and cell cultures. Under in vivo shrimp assay, both crude extract and the purified compound were active with ED50 values of 122.5 and 32.1 mu g/ml, respectively. When tested in four human cancer cell lines, namely, CL-187 (colon adenocarcinoma), MCF-7 (hormone-dependent breast carcinoma), MDA-MB-231 (hormone-independent breast carcinoma), and CRL-2547 (pancreatic carcinoma), the pure compound exhibited 1.5- to about 3-times greater cytotoxic activity than the crude extract. In all cancer cell lines, the LD50 values of crude extract ranged from 33.8 +/- 0.9 to 88.1 +/- 3.6 mu g/ml, while with pure compound the values ranged from 21.6 +/- 1.2 to 31.8 +/- 4.2 mu g/ml. In a noncancerous normal mouse adipose areolar (CCL-1 NCTC clone 929) cell line, the pure compound was found to have an LD50 value greater than 100 mu g/ml. Comparison of cytotoxic results of cell cultures revealed that the pure licamichauxiioic-B compound was relatively inactive in noncancerous cell line. The selectivity index for the pure licamichauxiioic-B compound is greater than 3.14 in all cancer cell lines tested.